/**
 *    Copyright (C) 2018-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#pragma once

#include "mongo/base/status_with.h"
#include "mongo/base/string_data.h"
#include "mongo/crypto/sha1_block.h"
#include "mongo/crypto/sha256_block.h"
#include "mongo/db/auth/sasl_mechanism_policies.h"
#include "mongo/db/auth/sasl_mechanism_registry.h"
#include "mongo/db/auth/user.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/service_context.h"

#include <string>
#include <tuple>
#include <utility>

#include <boost/move/utility_core.hpp>
#include <boost/optional/optional.hpp>

namespace mongo {

class SASLPlainServerMechanism : public MakeServerMechanism<PLAINPolicy> {
public:
    explicit SASLPlainServerMechanism(std::string authenticationDatabase)
        : MakeServerMechanism<PLAINPolicy>(std::move(authenticationDatabase)) {}

    boost::optional<unsigned int> currentStep() const override {
        return (unsigned int)1;
    }

    boost::optional<unsigned int> totalSteps() const override {
        return (unsigned int)1;
    }

private:
    StatusWith<std::tuple<bool, std::string>> stepImpl(OperationContext* opCtx,
                                                       StringData input) final;
};

class PLAINServerFactory : public MakeServerFactory<SASLPlainServerMechanism> {
public:
    using MakeServerFactory<SASLPlainServerMechanism>::MakeServerFactory;
    static constexpr bool isInternal = true;
    bool canMakeMechanismForUser(const User* user) const final {
        auto credentials = user->getCredentials();
        return !credentials.isExternal &&
            (credentials.scram<SHA1Block>().isValid() ||
             credentials.scram<SHA256Block>().isValid());
    }
};


}  // namespace mongo
